plat/common/aarch32/crash_console_helpers.S

   1 /*
   2  * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  */
   6
   7 /*
   8  * If a platform wishes to use the functions in this file it has to be added to
   9  * the Makefile of the platform. It is not included in the common Makefile.
  10  */
  11
  12 #include <asm_macros.S>
  13 #include <drivers/console.h>
  14
  15         .globl  plat_crash_console_init
  16         .globl  plat_crash_console_putc
  17         .globl  plat_crash_console_flush
  18
  19         /* -----------------------------------------------------
  20          * int plat_crash_console_init(void)
  21          * Use normal console by default. Switch it to crash
  22          * mode so serial consoles become active again.
  23          * NOTE: This default implementation will only work for
  24          * crashes that occur after a normal console (marked
  25          * valid for the crash state) has been registered with
  26          * the console framework. To debug crashes that occur
  27          * earlier, the platform has to override these functions
  28          * with an implementation that initializes a console
  29          * driver with hardcoded parameters. See
  30          * docs/porting-guide.rst for more information.
  31          * -----------------------------------------------------
  32          */
  33 func plat_crash_console_init
  34 #if defined(IMAGE_BL1)
  35         /*
  36          * BL1 code can possibly crash so early that the data segment is not yet
  37          * accessible. Don't risk undefined behavior by trying to run the normal
  38          * console framework. Platforms that want to debug BL1 will need to
  39          * override this with custom functions that can run from registers only.
  40          */
  41         mov     r0, #0
  42         bx      lr
  43 #else   /* IMAGE_BL1 */
  44         mov     r3, lr
  45         mov     r0, #CONSOLE_FLAG_CRASH
  46         bl      console_switch_state
  47         mov     r0, #1
  48         bx      r3
  49 #endif
  50 endfunc plat_crash_console_init
  51
  52         /* -----------------------------------------------------
  53          * void plat_crash_console_putc(int character)
  54          * Output through the normal console by default.
  55          * -----------------------------------------------------
  56          */
  57 func plat_crash_console_putc
  58         b       console_putc
  59 endfunc plat_crash_console_putc
  60
  61         /* -----------------------------------------------------
  62          * void plat_crash_console_flush(void)
  63          * Flush normal console by default.
  64          * -----------------------------------------------------
  65          */
  66 func plat_crash_console_flush
  67         b       console_flush
  68 endfunc plat_crash_console_flush